The development of various voice over IP protocols such as the H.323 Recommendation and the Session Initiation Protocol (SIP) has led to increased interest in multimedia conferencing. In such conferencing, typically, a more or less central server or other device manages the conference and maintains the various communications paths to computers or other client devices being used by parties to participate in the conference. Parties to the conference may be able to communicate via voice and/or video through the server and their client devices.
Instant messaging can provide an added dimension to multimedia conferences. In addition to allowing text chatting, instant messaging systems such as the Microsoft Windows Messenger™ system can allow for transfer of files, document sharing and collaboration, collaborative whiteboarding, and even voice and video. A complete multimedia conference can involve multiple voice and video streams, the transfer of files, marking-up of documents, and whiteboarding.
Presence-based communications applications are entering the mainstream telecommunications environment. In such applications, a user maintains one or more “contact lists” of other parties whose presence status is to be monitored and displayed to the user. When a contact's presence information indicates the contact is available, the user can then contact them. The user can then contact the other party for example via a telephone call.
In computer and telecommunications networks, presence information conveys availability and willingness of a user (called a presentity) to communicate. A users client provides presence information to a presence service to be stored and distributed to other users (called watchers) to convey its communication state. Presence information has wide application in voice over IP (VoIP) and instant messaging (IM).
A user client may publish a presence state to indicate its current communication status. This published state informs others that wish to contact the user of the user's availability and willingness to communicate. The most common use of presence today is the status indicator displayed on most instant messaging clients. A simpler everyday example is the ‘on-hook’ or ‘off-hook’ state of a telephone receiver, resulting in a distinctive ring tone (e.g., a busy signal) for a caller. Some states that offer extended information on the user's availability are “free for chat”, “away”, “do not disturb”, and “out to lunch”, which are often seen on many modern instant messaging clients. Rich information such as user mood and location may be also included. Presence is different from traditional ‘on-hook’ telephone status in that it deals with the user not the device (you want to talk to a person, not to a telephone).
Currently, when a user initiates a conference for a pre-designated list of conference attendees, some of the attendees may not be available to receive voice calls. As a result attendees that the user thought were necessary for a productive meeting are not included and time is wasted.
Furthermore, even in presence based communication systems where a user can look at the availability of the potential conferees, to do so is time-consuming. Even using a Tell-Me-When feature that notifies the user when a particular person is available for communications, the user needs to set up the feature on many people potentially, and keep track of when all of them are available. Again, this is time-consuming.
Therefore, it is desirable to have a system that allows a presence based communication system user to initiate a conference automatically when the desired parties are available.